This invention relates generally to mounting electrical devices in side-by-side relation and particularly relates to fuse holders or fuseblocks that are joined in side-by-side relation to effect a unitary arrangement of sequential fuseblocks.
Known fuse holders or fuseblocks furnish a molded body of insulating material that carries a pair of spaced apart clips to receive the end caps or blades of a fuse. The body supplies a base that carries the clips and a wall or pair of walls upstanding from the sides of the base. The base and sidewalls insulate the fuse clips and associated electrical connectors of the fuseblock from other parts that could otherwise intrude thereabouts to prevent short circuits and electrical shock to personnel.
Many installations require plural fuses and fuseblocks, and for convenience modular fuseblocks often are mounted next to one another in a series of side-by-side relationships, preferably joined in a unitary structure.
U.S. Pat. No. 3,993,395 to Taylor discloses a fuseblock structure constructed and arranged to engage with an adjacent fuseblock of like construction and become joined therewith through mating pairs of downwardly opening dovetail recesses or pockets and upwardly directed dovetail prongs. One side of the fuseblock will present the pair of dovetail pockets and the other side will present the pair of dovetail prongs. Slipping the two pockets down onto the two prongs then will join together the two fuseblocks in a unitary structure. The fuseblock of this patent furnishes a single sidewall extending above the pair of pockets with the one sidewall of one fuseblock forming a barrier between the fuses, clips and connectors of two joined fuseblocks. A separate sidewall member having a like pair of pockets provides the last end wall for the joined series of fuseblocks.
U.S. Pat. No. 4,082,408 to Angelis discloses a similar fuseblock structure having, however, a pair of sidewalls and only one downwardly opening dovetail pocket on one sidewall and one upwardly directed prong arranged on the opposite side wall. Again, the fuseblocks are joined by slipping the pocket down on the prong, both the pocket and prong being centrally located on the sides of the fuseblock.
A problem arises, however, with this downwardly opening pocket and prong arrangement. When one or more fuseblocks are fastened on a flat panel, additional fuseblocks cannot readily be joined to the series of fuseblocks on the side presenting the pocket or pockets; the downwardly opening pocket is not accessible from the side or from above to slip an upwardly directed prong therein. This requires that most if not all the fuseblocks be un-fastened from the flat panel to which they are attached. The upwardly directed prong of the additional fuseblock then must be joined with the downwardly directed pocket or pockets of the end fuseblock, and all of the fuseblocks must be re-fastened to the panel with the previously removed screws. This procedure wastes time and consumes labor.
Adding another fuseblock on the side or end with the exposed prong or prongs occurs by simply slipping the pocket or pockets down on the exposed prong or prongs and then fastening the fuseblock to the panel with an additional screw. The side of the fuseblock with the exposed prong or prongs, however, often is unavailable when the prong or prongs abut a cabinet wall or extend to the edge of the available space for the fuseblocks. In the field or in the factory, joining a fuseblock to an existing fuseblock or joined assembly of fuseblocks thus can be an expensive operation.
In addition to mounting fuseblocks on a flat panel, fuseblocks also have been mounted on channel members. The channel members typically furnish a base plate, fastened to an underlying support with such as screws, and a pair of upstanding rails of standard configuration or configurations. For mounting, the bottom front lip of the fuseblock engages with an edge of the front or lower rail, and the fuseblock rotates backwardly to snap a bottom back lip into engagement with an edge of the back or upper rail. The fuseblock exerts a force against the rails positively to fix the fuseblock in position along the channel member. This force typically results from the dimensions between the lips being slightly less than the dimensions between the engaged edges of the rails and the channel member compressing or torquing the fuseblock material to express the force.
U.S. Pat. No. 3,245,029 discloses a terminal block assembly for flat base or channel mounting. The disclosed assembly furnishes an end section and a terminal section that slide and nest against one another on the channel rails. The two sections are fastened in side-by-side nested relationship by screw clamps engaging the rails of the channel member.
A problem with the previously described fuseblocks and this last described terminal block assembly mounted on a channel member is the absence of simple joint structure for joining fuseblocks together, side-by-side in a unit on a channel member. Rotation of a fuseblock to mount the same on a channel member appears to preclude a vertical straight dovetail joint. Sliding fuseblocks together along a channel member also appears to preclude a vertical dovetail joint. Yet a need exists for some joint structure that can be used to join plural fuseblocks into a unit for flat panel and channel member mounting. A universal fuseblock design incorporating such a joint structure then could replace several different fuseblock designs presently required to obtain the described flat panel and channel member mountings.